tf.image.adjust_saturation

This is a convenience method that converts an RGB image to float
representation, converts it to HSV, add an offset to the saturation channel,
converts back to RGB and then back to the original data type. If several
adjustments are chained it is advisable to minimize the number of redundant
conversions.

image is an RGB image. The image saturation is adjusted by converting the
image to HSV and multiplying the saturation (S) channel by
saturation_factor and clipping. The image is then converted back to RGB.